Borexino Solar Neutrino Detector

A photo of the scintillator vessel and shroud inside Borexino Solar Neutrino Detector at Gran Sasso in Italy. The detector consists of nested nylon vessels fabricated at Princeton that hold liquid scintillator. Neutrinos excite the scintillator causing the aromatic scintillator to fluoresce. The light is collected by 2200 phototubes mounted on a 14 m diameter stainless steel sphere. This detector permitted the first direct measurement of the 7Be solar neutrino flux by an international collaboration including the Chemical Engineering Department at Princeton. For more details see:

This photo was taken during the scintillator displacement of water in the Borexino detector. The photo is taken form a camera mounted on the stainless steel sphere and looks out between light cones. The nylon vessels which hold the scintillator can be seen to be half full of water at the bottom and scintillator at the top. The support and guide ropes can be seen surrounding both the inner and outer nylon vessels. At the top of the inner nylon vessel is the pipe which feeds the scintillator into the inner vessel.